/*
 * Copyright (c) 1998-2011 Caucho Technology -- all rights reserved
 *
 * This file is part of Resin(R) Open Source
 *
 * Each copy or derived work must preserve the copyright notice and this
 * notice unmodified.
 *
 * Resin Open Source is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * Resin Open Source is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE, or any warranty
 * of NON-INFRINGEMENT.  See the GNU General Public License for more
 * details.
 *
 * You should have received a copy of the GNU General Public License
 * along with Resin Open Source; if not, write to the
 *   Free SoftwareFoundation, Inc.
 *   59 Temple Place, Suite 330
 *   Boston, MA 02111-1307  USA
 *
 * @author Scott Ferguson
 */

package com.caucho.xsl.fun;

import com.caucho.xpath.Expr;
import com.caucho.xpath.ExprEnvironment;
import com.caucho.xpath.XPathException;
import com.caucho.xpath.XPathFun;
import com.caucho.xpath.pattern.AbstractPattern;

import org.w3c.dom.Node;

import java.util.ArrayList;

/**
 * The system-property(...) function.
 */
public class SystemPropertyFun extends XPathFun {
  /**
   * Evaluate the function.
   *
   * @param pattern The context pattern.
   * @param args The evaluated arguments
   */
  public Object eval(Node node, ExprEnvironment env, 
                     AbstractPattern pattern, ArrayList args)
    throws XPathException
  {
    if (args.size() < 1)
      return "";

    String name = Expr.toString(args.get(0));

    if (name.equals("xsl:version"))
      return new Double(1.0);
    else if (name.equals("xsl:vendor"))
      return "Caucho Technology";
    else if (name.equals("xsl:vendor-url"))
      return "http://www.caucho.com";
    else
      return System.getProperty(name);
  }
}
